Process of making calcium aluminate and other products.



S. PEAOOOK. PROCESS OI MAKING CALCIUM ALUMINATE AND OTHER PRODUCTS.

APPLICATION FILED JUNE 17, 1909.

Patented Aug. 8, 1911.

I To on whom it may concern:

UNITE STATES {PATENT OFFICE.

SAMUEL PEAGOCK, or CHICAGO, rumors; n's'smivon- T0 AMERICAN CYANAMIlJ comrnnv, on NEW YORK, N. Y., A CORPORATION OF'MAINE.

PROCESS or MAR-mo CALCIUMALUMINATE AND OTHER rnonncrrs.

Specification of Letters Patent. Patented Aug, 8, 1911, Application filed June 17, 1909. Serial No. 502,793.

Be it known that I, SAMUEL PE iQOCK, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Processes of Making Calcium Aluminate and other Products; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others-skilled in the art to which it appertains to make and use the same.

- This invention relates to a process for making calcium aluminate, Ca A1 0,, and the pentoxid of phosphorus, P 0 from alumina, and calcium phosphate, and has for its object to produce a simple and comparatively cheap process for making these products in a single operation.

To this end the invention consists in the novel steps and combinations of steps constituting my process, more fully hereinafter disclosed and particularly pointed out in the claims. v

Referring to the accompanying drawings, forming a part of this specification, in which the figure 1s a sectional diagrammatic view of a. well known type of furnace suitable for carrying out my purpose :1 represents any suitable supports; 2 stationary end closures provided with an inlet 3 for the fuel, and an exit 4. for the gases; 5 a rotating barrel part,

6 means for rotating the same; 7 a hopper for receiving the rock mixture, 8 a screw .conveyer for the same, and 9 a delivery spout leading into the furnace.

10 represents a suitable delivery passage for the calcium aluminate; and 11 a suitable receptacle for receiving the same.

For the purposes of this process bauxite, or other cheap aluminous material, and phosphate took, both of low grade, may be used,

and the following analysis may be taken as a basis of calculation v lBauiptta. Phosphate. Al O 52.92 p. ct. j 2.74 p. ct; F80 7.66 .52 J Si) 8 10.17' 4.06 cao u 44.55 e PO u 34.30 'rio' u 2 30 00. -1111: 3.19 H 0 26 .90 1 1.39

The reactions involved in the aluminate manufacture are three molecules of CaO, or in other words, a

pound of CaO in each of the three reactions,

respectively, requires of:

Alumina Al O 1 .83 lbs. Ferric oxid, Fe,O 2.85 Silica,'SiO- .36

That is to say, 2,000 lbs. of phosphate rock, analyzing as above, will contain and require Ca() 891 lbs. A1 0 requiring of CaO 30 lbs. Fe O C t t 4 t Si 81 225.

I Total CaO required c 259 lbs.

As 2,000 lbs. of the above phosphate rock contain 891 lbs. of 00.0, and only269 lbs. of

' CaO- are required by itsown alumina, ferric oxid, and silica, there remains 632 lbs. of I CaO to react with the bauxite in the particular example given. But, 100 lbs. of bauxite contains and requires CaO as follows From this it is clear that since there are 632 .lbs. of surplus 09.0 from the 2,000 lbs. of phosphate rock to react with the'bauxite, that the proper proportions of the furnace mixture for this process are: i v Phosphate rock 2,000 lbs.

Bauxi e 1,053

A: chemically balanced mixture of this nature being produced ground to the same fineness, and prepared, in allrespects as are I the'ingredients in'the ,making of Portland phate substantially v nates Ca Al O and Ca Al o takes place, the mass is more or less viscous I layers the phosphoric anhydrid'will not escially is thistrue when the containing vessel accordance with the following equation the rotary furnace above disclosedan c on,

cement, I pass said mixture through and heat it in a suitable furnace, preferably like' the one-shown, to about 1400 O., to 1500" 0., when the alumina reacts with the lime phosfollowing equations I v 3CaO.P,O ,+3Al O,:3CaAl,O -|P O p The small quantity of ferric oxid present at the same temperature reacts substantially The silica reacts substantially .as follows':

The calcium aluminate, CaAl O is mixed with small quantities of 'CaFe O and Ca SiO but these latter compounds are in such small proportions that they do not affect the commercial value of theproduct; and when the reaction is completed it is passed through the exit'10 into suitable receptacles and finished for the market in the usual way. The pentoxid of phosphorus P 0 passes out of. the exit 4 and is .collected in any suitable. manner, as by absorption in" water, or by a condensation method. From such a furnace mixture, assuming an efficiency of 95%, the phosphoric acid produced, in the example given, will be 652 lbs., for each short ton of phosphate rock and such a mixture containing 3,053 lbs. of phosphate rock and bauxite, as above, will produce 1,989 lbs. of the crude calcium aluminate.

Of course, the above proportions are merely illustrative and it is to'be understood that with different supplies ofbauxite and of phosphate, different proportions will,obtain. It. is also to be understood that my invention is not limited to mono calcium salts given. as examples in the above reactions, for it is evident that I may employ the same ingredients in the proper proportions to form the various well known acid or basic calcium salts, such for example, as the di and tri calcium alumi- In charges "such. as the above if fusion or plastic and unless it is formed into thin cape in any appreciable quantities. Espeis deep enough t'o cause the fused mass to exert a hydrostatic pressure, for the latter seems to have the effect of reversin the chemical equilibrium and therefore 0 preventing the separation of thejP O In order to avoid the above obiections 'I-em by in accordance with the the interior of which the material forms since these layers are revolved with the furnace, if they are fused, owing to 'the reduction of pressure as they are carried out of the molten mass the gas easily escapes and thin. layers, whether it is fused or not; and

no difficulty is therefore experienced in producing the same inquantity. p

The process for making pentoxid of phosphorus, calciumsilicate and aluminates, by

heating phosphate rock and silica, or cal-' mina, described herein is claimed in my copending application #515,803 and the process of making calcium ferrite by heating .cium phosphate andcrude silicate-of alu-.

phosphate rock and iron oxid as shown herein is described and claimed in my Patent No. 988,137. I l

What I claim 'is: 1..In the process of producing the 'pen- 'toxid of phosphorus and calcium aluminate from a source of alumina and lime ph0sphate in'a single operation which consists in mixing alumina and phosphate in such proportions that chemically equivalent quantities of calcium oxid will be supplied tothe alumina present in the mixture to form calcium aluminate; heating said mixture to a temperature insuflicient to fuse the charge, but suflicient to form said aluminate and to free said pentoxid from the lime phosphate; while forming the heated mixture into'thin layers to permit said pentoxid to escape, substantially as described. J

2. In the process of producing the pentoxid of phosphorus and calcium aluminate from a source of alumina and phosphate rock in a single operation which consists in mixing an aluminiferous material and calcium phosphate in such proportions that sufficientcalcium oxid will be present in the mixture to chemically react with substan: tially allthe alumina and ferric oxidthat may also be present; in heating the mixture to a temperature insuflicient to fuse the charge, but sufficient to bring about, such 'reactions and to free said pentoxid from saidphosphate, while forming the heated mixture into thin layers to permit said pentoxid to escape, substantially as described.

3-. In the process of producing P 0 and CaAl Q, from aluminiferous material and phosphate rock in a single operation which consists in mixing said material and calcium phosphate in such proportions that sufiicient CaO will be present in the mixture to chemically react with all the A1 0 the Fe O andthe siO that may-be also pres ent in said mixture; in heating said mixture to. a temperature sufiicientto bring about such reactions andto free the I Q contained in the phosphate; while forming the heated mixture intothin layers to permit said pentoxid to escape, substantially as de- 4. In the process of producing P 0 and and in collecting'the CaAl O formed; sub- 10 CaA1 O from bauxite and phosphate rock stantially as described.

in a single operation which consists in suit- In testimony whereof, I aflix my signaably mixing substantially 2,000 lbs. of said ture, in presence of two witnesses. 5 rock with 1053 lbs.- of ba uxite, in suitably SAMUEL PEACOCK.

heating the said mixture to substantially 1500 C.; while forming the heated mixture Witnesses: I

into thin layers to permit said pentoxid to T. A. WITHERSIfOON, escape, in collecting the P 0 driven 0a; ROLAND C. Bpo'rH. 

